Injector resonator for a gas turbine engine

ABSTRACT

A fuel injector for a combustor of a gas turbine engine is disclosed herein. In embodiments, the fuel injector includes an injector head, a stem, a fuel passage, a fitting, a fuel inlet, and a resonator. The stem extends from the injector head. The fuel passage extends within the towards the injector head. The fitting is joined to the stem distal to the injector head. The fuel inlet fluidly connects the fitting to the fuel passage. The resonator includes a resonator body enclosing a resonator cavity and a resonator neck passage that fluidly connects the resonator cavity to the fuel passage adjacent to the fuel inlet.

TECHNICAL FIELD

The present disclosure generally pertains to a resonator, and isdirected toward a resonator for an injector of a gas turbine engine.

BACKGROUND

Gas turbine engines include compressor, combustor, and turbine sections.During operation of the gas turbine engine combustion oscillations maydamage or reduce the operating life of the components of the combustor.Combustion oscillations may be the result of resonance within the fuelinjectors.

U.S. Pat. No. 8,789,372 to Johnson, et al. discloses a system that mayinclude a turbine engine. The turbine engine may include a fuel nozzle.The fuel nozzle may include an air path. The fuel nozzle may alsoinclude a fuel path such that the fuel nozzle is in communication with acombustion zone of the turbine engine. Furthermore, the fuel nozzle mayinclude a resonator. The resonator may be disposed in the fuel nozzledirectly adjacent to the combustion zone.

The present disclosure is directed toward overcoming one or more of theproblems discovered by the inventors or that is known in the art.

SUMMARY OF THE DISCLOSURE

A fuel injector for a combustor of a gas turbine engine is disclosedherein. In embodiments, the fuel injector includes an injector head, astem, a fuel passage, a fitting, a fuel inlet, and a resonator. The stemextends from the injector head and includes a fitting portion distal tothe injector head. The fuel passage extends within the stem from thefitting portion towards the injector head. The fitting is joined to thefitting portion. The fuel inlet fluidly connects the fitting to the fuelpassage. The resonator is integral to the stem. The resonator includes aresonator body and a resonator neck passage. The resonator body enclosesa resonator cavity. The resonator neck passage fluidly connects theresonator cavity to the fuel passage adjacent to the fuel inlet at thefitting portion.

A method for retrofitting a fuel injector including an injector head anda stem extending from the injector head is also disclosed. Inembodiments, the method includes machining a hole through the stem to astem fuel passage adjacent a fuel inlet fluidly connected to the stemfuel passage. The fuel inlet is located at a fitting portion of the stemat an end of the stem opposite the injector head. The method alsoincludes metallurgically bonding a resonator to the fitting portion. Theresonator includes a resonator body forming a resonator cavity fluidlyconnected to the stem fuel passage adjacent to the fuel inlet at thefitting portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary gas turbine engine.

FIG. 2 is a perspective view of an embodiment of the fuel injectorincluding a resonator.

FIG. 3 is a cross-sectional view of a portion of the fuel injector ofFIG. 2 including the resonator taken along line shown in FIG. 2.

FIG. 4 is a perspective view of the fuel injector including an alternateembodiment of the resonator.

FIG. 5 is a cross-sectional view of a portion of the fuel injector ofFIG. 4 including the alternate embodiment of the resonator taken alongline V-V shown in FIG. 4.

FIG. 6 is a cross-sectional view of the fuel injector including anotherembodiment of the resonator.

FIG. 7 is a flowchart of a method for retrofitting a fuel injector toinclude a resonator.

DETAILED DESCRIPTION

The systems and methods disclosed herein include a resonator for a fuelinjector. In embodiments, the fuel injector includes a fuel passage withan inlet for providing fuel into the fuel passage. The resonatorincludes a resonator body that forms a resonator cavity and a resonatorneck passage that fluidly connects the resonator cavity to the fuelpassage where the fluid connection is adjacent to the fuel inlet.Connecting the resonator neck passage adjacent to the fuel inlet mayminimize the resonance of the fuel between the fuel passage and theflame, which may reduce combustor oscillations and increase theoperating life of the components in the combustor.

FIG. 1 is a schematic illustration of an exemplary gas turbine engine100. Some of the surfaces have been left out or exaggerated (here and inother figures) for clarity and ease of explanation. Also, the disclosuremay reference a forward and an aft direction. Generally, all referencesto “forward” and “aft” are associated with the flow direction of primaryair (i.e., air used in the combustion process), unless specifiedotherwise. For example, forward is “upstream” relative to primary airflow, and aft is “downstream” relative to primary air flow.

In addition, the disclosure may generally reference a center axis 95 ofrotation of the gas turbine engine, which may be generally defined bythe longitudinal axis of its shaft 120 (supported by a plurality ofbearing assemblies 150). The center axis 95 may be common to or sharedwith various other engine concentric components. All references toradial, axial, and circumferential directions and measures refer tocenter axis 95, unless specified otherwise, and terms such as “inner”and “outer” generally indicate a lesser or greater radial distance fromcenter axis 95, wherein a radial 96 may be in any directionperpendicular and radiating outward from center axis 95.

A gas turbine engine 100 includes an inlet 110, a shaft 120, acompressor 200, a combustor 300, a turbine 400, an exhaust 500, and apower output coupling 50. The gas turbine engine 100 may have a singleshaft or a dual shaft configuration.

The compressor 200 includes a compressor rotor assembly 210, compressorstationary vanes (stators) 250, and inlet guide vanes 255. Thecompressor rotor assembly 210 mechanically couples to shaft 120. Asillustrated, the compressor rotor assembly 210 is an axial flow rotorassembly. The compressor rotor assembly 210 includes one or morecompressor disk assemblies 220. Each compressor disk assembly 220includes a compressor rotor disk that is circumferentially populatedwith compressor rotor blades. Stators 250 axially follow each of thecompressor disk assemblies 220. Each compressor disk assembly 220 pairedwith the adjacent stators 250 that follow the compressor disk assembly220 is considered a compressor stage. Compressor 200 includes multiplecompressor stages. Inlet guide vanes 255 axially precede the compressorstages.

The combustor 300 includes a combustion chamber 390 and one or more fuelinjectors 310. The fuel injectors 310 may be upstream of the combustionchamber 390 and may be annularly arranged about center axis 95.

The turbine 400 includes a turbine rotor assembly 410 and turbinenozzles 450. The turbine rotor assembly 410 mechanically couples to theshaft 120. In the embodiment illustrated, the turbine rotor assembly 410is an axial flow rotor assembly. The turbine rotor assembly 410 includesone or more turbine disk assemblies 420. Each turbine disk assembly 420includes a turbine disk that is circumferentially populated with turbineblades. Turbine nozzles 450 axially precede each of the turbine diskassemblies 420. Each turbine disk assembly 420 paired with the adjacentturbine nozzles 450 that precede the turbine disk assembly 420 isconsidered a turbine stage. Turbine 400 includes multiple turbinestages.

The exhaust 500 includes an exhaust diffuser 510 and an exhaustcollector 520. The power output coupling 600 may be located at an end ofshaft 120.

FIG. 2 is a perspective view of an embodiment of the fuel injector 310including a resonator 350. The fuel injector may also include aninjector head 330, a stem 320, fittings 315, a flange 311, and a fueltube 317. The injector head 330 supplies fuel to the combustion chamber390 for combustion. The stem 320 may extend from the injector head 330and supplies the fuel to the injector head 330. The stem 320 may beformed from a piece of bar stock. The stem 320 may include a fittingportion 325 where one or more fittings 315 are connected to the stem320. The fitting portion 325 may be at the opposite end of the stem 320from the injector head 330 and may be the portion of the stem 320extending beyond the flange 311 opposite the location of the injectorhead 330.

The fittings 315 supply fuel to the fuel injector 310 from a fuelsource. The flange 311 may be joined to the stem 320, such as bymetallurgical bonding. The flange 311 may include mounting holes 312 forsecuring the fuel injector 310 to the gas turbine engine 100. The fueltube 317 may form part of the flow path of the fuel to the injector head330 and may connect between the stem 320 and the injector head 330.

The resonator 350 may be integral to the stem 320, such as unitary withthe stem 320 or metallurgically bonded to the stem 320. In theembodiment illustrated in FIG. 2, the resonator 350 and the stem 320 area unitary piece and may be formed from the same piece of bar stock. Theresonator 350 may adjoin the fitting portion 325.

FIG. 3 is a cross-sectional view of a portion of the fuel injector 310of FIG. 2 including the resonator 350 taken along line shown in FIG. 2.The stem 320 may include one or more stem fuel passages that extendthrough the stem 320 and deliver fuel from the fittings 315 to ortowards the injector head 330. In the embodiment illustrated, the stemfuel passages include a pilot fuel passage 321 and a main fuel passage322 for supplying pilot fuel and main fuel to the injector head 330respectively. In some embodiments, the fuel tube 317 shown in FIG. 2 mayconnect between the pilot fuel passage 321 and the injector head 330.

The fuel injector 310 may include stem fuel inlets 316 where thefittings 315 connect to the stem fuel passages. The stem fuel inlets 316may form a transition between the fitting and a fuel passage. The stemfuel inlets 316 may include a flow restrictor, such as an orifice or afilter. In the embodiment illustrated, the stem fuel inlets 316 arelocated in the fittings 315 adjacent to the stem fuel passages and aredistal to the injector head 330.

The fuel injector 310 may also include plugs 326. Each stem fuel passagemay be machined into the stem 320. The plugs 326 may be inserted intothe stem fuel passages and joined to the stem 320, such as bymetallurgical bonding, to cap the ends of the stem fuel passages distalto the injector head 330.

The resonator 350 may include a resonator body 352, a resonator cavity353, and a resonator neck passage 351. The resonator body 352 mayinclude a resonator base 354, a resonator wall 355, and a resonator cap356. The resonator base 354 may be adjacent to, such as next to oradjoining, the fitting portion 325. In the embodiment illustrated, theresonator base 354 includes the plugs 326 for the stem fuel passages.The resonator wall 355 may extend from the resonator base 354 in thedirection opposite the fitting portion 325. The resonator wall 355 maybe a hollow tube, such as a round tube (hollow cylinder), a square tube,and the like. The resonator cap 356 may be located at the end of theresonator wall 355 opposite the resonator base 354.

The resonator base 354, the resonator wall 355, and the resonator cap356 may be integral to each other and to the stem 320. In the embodimentillustrated, the resonator base 354 (other than the plugs 326) and theresonator wall 355 are unitary to the stem 320, such as formed in thesame bar stock; the resonator cap 356 is joined to the resonator wall355, such as metallurgically bonded to the resonator wall 355. In otherembodiments, the resonator base 354 (other than the plugs 326) isunitary to the stem 320, while the resonator wall 355 is joined to theresonator base 354, such as metallurgically bonded to the resonator base354; and the resonator cap 356 may be unitary or joined to the resonatorwall 355.

The resonator body 352 including the resonator base 354, the resonatorwall 355, and the resonator cap 356 may form and enclose the resonatorcavity 353. In the embodiment illustrated, the resonator cavity 353includes a cylindrical shape. In other embodiments, the resonator cavity353 may include, inter alia, a cuboidal shape, a prismatic shape, aspheroidal shape, or a conical shape.

The resonator neck passage 351 extends from a fuel passage, such as astem fuel passage or an injector head fuel passage, to the resonatorcavity 353. In the embodiment illustrated, the resonator neck passage351 extends from the pilot fuel passage 321. The resonator neck passage351 may include, inter alia, a cylindrical shape, cuboidal shape, orprismatic shape. In the embodiment illustrated, the resonator neckpassage 351 extends through the resonator base 354, such as through aplug 326. The resonator neck passage 351 may fluidly connect theresonator cavity 353 to a fuel passage adjacent to a fuel inlet, such asa stem fuel inlet 316 or an injector head fuel inlet.

FIG. 4 is a perspective view of the fuel injector 310 including analternate embodiment of the resonator 350. FIG. 5 is a cross-sectionalview of a portion of the fuel injector 310 of FIG. 4 including thealternate embodiment of the resonator 350 taken along line V-V shown inFIG. 4. Referring to FIGS. 4 and 5, the resonator base 354 may beseparate from the stem 320. The resonator 350 may also include aresonator tube 357 extending from the resonator body 352. The resonatortube 357 may extend integrally from the resonator body 352 to the stem320. In the embodiment illustrated, the resonator tube 357 extends fromthe resonator base 354. As illustrated in FIG. 5, the resonator tube 357may include the resonator neck passage 351 and may fluidly connect theresonator cavity 353 to a fuel passage, such as the pilot fuel passage321, adjacent to a fuel inlet, such as a stem fuel inlet 316.

In the embodiment illustrated in FIGS. 4 and 5, the resonator 350 isintegral to the stem 320 via joining, such as metallurgical bonding, theresonator tube 357 to the stem 320 at the end of a fuel passage. Theresonator tube 357 may replace the plug 326 at the end of the fuelpassage or may be inserted into a bore in the plug 326 and joined, suchas metallurgically bonded, to the plug 326.

The axis of the resonator tube 357 and the resonator body 352 may bealigned on the same axis along with the fuel passage. The fuel passagemay not be coaxial to the stem 320. Thus, in embodiments, the axis ofthe resonator 350 and of the stem 320 may be offset.

FIG. 6 is a cross-sectional view of the fuel injector 310 includinganother embodiment of the resonator 350. Referring to FIG. 6, theinjector head 330 may include a fuel gallery 332 that distributes thefuel within the injector head 330. All other interior details of theinjector head 330 are not shown for ease of explanation. In theembodiment illustrated, the fuel gallery 332 includes an annular shaperevolved about an axis 399. The fuel tube 317 may extend between a stemfuel passage, such as the pilot fuel passage 321 and the fuel gallery332. The injector head 330 may also include an injector head fuel inlet318 where the fuel tube 317 connects to an injector fuel passage, suchas the fuel gallery 332.

In the embodiment illustrated in FIG. 6, the resonator neck passage 351fluidly connects the resonator cavity 353 to the fuel gallery 332. Theresonator neck passage 351 and the resonator tube 357 may connect to thefuel gallery 332 adjacent to the injector head fuel inlet 318. In theembodiment illustrated in FIG. 6, the resonator body 352 may bepositioned adjacent to the injector head 330 and may be situated so asto not obstruct airflow into the injector head 330.

INDUSTRIAL APPLICABILITY

Gas turbine engines may be suited for any number of industrialapplications such as various aspects of the oil and gas industry(including transmission, gathering, storage, withdrawal, and lifting ofoil and natural gas), the power generation industry, cogeneration,aerospace, and other transportation industries.

Referring to FIG. 1, a gas (typically air 10) enters the inlet 110 as a“working fluid”, and is compressed by the compressor 200. In thecompressor 200, the working fluid is compressed in an annular flow path115 by the series of compressor disk assemblies 220. In particular, theair 10 is compressed in numbered “stages”, the stages being associatedwith each compressor disk assembly 220. For example, “4th stage air” maybe associated with the 4th compressor disk assembly 220 in thedownstream or “aft” direction, going from the inlet 110 towards theexhaust 500). Likewise, each turbine disk assembly 420 may be associatedwith a numbered stage.

Once compressed air 10 leaves the compressor 200, it enters thecombustor 300, where it is diffused and fuel is added. Air 10 and fuelare injected into the combustion chamber 390 and combusted. An air andfuel mixture is supplied via fuel injector 310. Energy is extracted fromthe combustion reaction via the turbine 400 by each stage of the seriesof turbine disk assemblies 420. Exhaust gas 90 may then be diffused inexhaust diffuser 510, collected and redirected. Exhaust gas 90 exits thesystem via an exhaust collector 520 and may be further processed (e.g.,to reduce harmful emissions, and/or to recover heat from the exhaust gas90).

A resonance may be linked between the flame and a fuel passage in thefuel injector 310, which may result in combustor oscillations. Fluidlyconnecting the resonator 350 to a fuel passage in the fuel injector 310,such as a pilot fuel passage 321 or a fuel gallery 332, may counteractthe resonance between the flame and the fuel passage and may reduce orprevent combustor oscillations.

Connecting the resonator 350 to a fuel passage adjacent to a fuel inletof the fuel injector 310, such as the stem fuel inlet 316 or theinjector head fuel inlet 318 may place the resonator neck passage 351adjacent to an antinode of the linked resonance between the flame andthe fuel passage, which may increase the overall effectiveness of theresonator 350 and further reduce combustor oscillations. Counteractingand reducing combustor oscillations may increase the durability andoperating life of the combustor 300 and the various components of thecombustor 300.

FIG. 7 is a flowchart of a method for retrofitting a fuel injector 310to include a resonator 350. The method includes machining a hole 327through the stem 320 to a stem fuel passage adjacent a stem fuel inlet316 fluidly connected to the stem fuel passage, the stem fuel inlet 316located at a fitting portion 325 of the stem 320 at an end of the stem320 opposite the injector head 330 at step 610. Referring to FIG. 5,machining the hole 327 through the stem 320 may include machiningthrough the fitting portion 325, such as machining through the plug 326or removing the plug 326. The hole 327 may have the same diameter as thestem fuel passage or may form a counterbore relative to the stem fuelpassage.

The method also includes metallurgically bonding the resonator 350 tothe fitting portion 325 where the resonator 350 includes a resonatorbody 352 forming a resonator cavity 353 fluidly connected to the stemfuel passage adjacent to the stem fuel inlet 316 at the fitting portion325 at step 620.

In some embodiments, step 620 includes metallurgically bonding aresonator wall 355 of the resonator body 352 to the fitting portion 325.In these embodiments, the resonator body 352 includes a resonator cap356 integral to the resonator wall 355 and the hole 327 forms theresonator neck passage 351 that fluidly connects the resonator cavity353 to the stem fuel passage adjacent to the stem fuel inlet 316.

In other embodiments, the resonator 350 includes a resonator tube 357extending from the resonator body 352 and step 620 includesmetallurgically bonding the resonator 350 to the fitting portion 325includes inserting the resonator tube 357 into the hole 327 andmetallurgically bonding the resonator tube 357 to the stem 320. In theseembodiments, the resonator tube 357 includes the resonator neck passage351 that fluidly connects the stem fuel passage to the resonator cavity353.

The preceding detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. The described embodiments are not limited to use inconjunction with a particular type of gas turbine engine or a particularcombustion chamber. Hence, although the present disclosure, forconvenience of explanation, depicts and describes particular embodimentsof the fuel injector and resonator for a combustion chamber, it will beappreciated that the fuel injector and resonator in accordance with thisdisclosure can be implemented in various other configurations, can beused with various other types of combustion chambers and gas turbineengines, and can be used in other types of machines. Further, theresonator may be used in conjunction with a pilot or main fuel passageand can be used with gas or liquid fuel passages. Any explanation inconnection with one embodiment applies to similar features of otherembodiments, and elements of multiple embodiments can be combined toform other embodiments. Furthermore, there is no intention to be boundby any theory presented in the preceding background or detaileddescription. It is also understood that the illustrations may includeexaggerated dimensions to better illustrate the referenced items shown,and are not consider limiting unless expressly stated as such.

What is claimed is:
 1. A fuel injector for a combustor of a gas turbineengine, the fuel injector comprising: an injector head; a stem extendingfrom the injector head, the stem including a fitting portion distal tothe injector head; a fuel passage extending within the stem from thefitting portion towards the injector head; a fitting joined to thefitting portion; a fuel inlet fluidly connecting the fitting to the fuelpassage; and a resonator integral to the stem, the resonator including aresonator body enclosing a resonator cavity, and a resonator neckpassage fluidly connecting the resonator cavity to the fuel passageadjacent to the fuel inlet at the fitting portion.
 2. The fuel injectorof claim 1, wherein the resonator body includes a resonator base, aresonator wall extending from the resonator base, and a resonator capopposite the resonator base.
 3. The fuel injector of claim 2, whereinthe resonator base is unitary to the stem and the resonator neck passageis formed in the resonator base.
 4. The fuel injector of claim 3,wherein the resonator wall is unitary to the stem and the resonator baseand the resonator cap is metallurgically bonded to the resonator wall.5. The fuel injector of claim 3, wherein the resonator wall and theresonator cap are unitary and the resonator wall is metallurgicallybonded to the resonator base.
 6. The fuel injector of claim 3, whereinthe resonator base includes a plug situated between the fuel passage andthe resonator cavity and the resonator neck passage is formed in theplug.
 7. The fuel injector of claim 1, wherein the resonator furtherincludes a resonator tube extending from the resonator body to the stem,the resonator tube including the resonator neck passage.
 8. The fuelinjector of claim 7, wherein the resonator body and the resonator tubeare unitary, and wherein the resonator tube is metallurgically bonded tothe fitting portion.
 9. A fuel injector for a combustor of a gas turbineengine, the fuel injector comprising: an injector head; a stem extendingfrom the injector head; a fuel passage extending within the fuelinjector; a fuel inlet fluidly connected to the fuel passage forproviding fuel to the fuel passage; and a resonator including aresonator body enclosing a resonator cavity, and a resonator neckpassage fluidly connecting the resonator cavity to the fuel passageadjacent to the fuel inlet.
 10. The fuel injector of claim 9, whereinthe fuel passage is a stem fuel passage extending within the stem fromthe stem toward the injector head and the fuel inlet is at an end of thefuel passage distal to the injector head.
 11. The fuel injector of claim10, wherein the fuel passage is a pilot fuel passage for providing pilotfuel to the injector head and the fuel inlet is located in a fittingjoined to the stem.
 12. The fuel injector of claim 10, wherein theresonator body is integral to the stem.
 13. The fuel injector of claim12, wherein the resonator body includes a resonator base that is unitaryto the stem and wherein the fuel passage extends through the resonatorbase.
 14. The fuel injector of claim 13, wherein resonator body includesa resonator wall that is unitary to the resonator base and a resonatorcap that is metallurgically bonded to the resonator wall.
 15. The fuelinjector of claim 13, wherein the resonator body includes a resonatorwall and a resonator cap that are unitary and wherein the resonator wallis metallurgically bonded to the resonator base.
 16. The fuel injectorof claim 10, wherein the resonator further includes a resonator tubeextending integrally from the resonator body to the stem, the resonatortube including the resonator neck passage, and wherein the resonatortube is metallurgically bonded to the stem.
 17. The fuel injector ofclaim 9, wherein the fuel passage is a fuel gallery in the injector headand the fuel inlet supplies fuel from a stem fuel passage to the fuelgallery, and wherein the resonator further includes a resonator tubethat includes the resonator neck passage, the resonator tube extendingfrom the resonator body to the injector head.
 18. A method forretrofitting a fuel injector including an injector head and a stemextending from the injector head, the method comprising: machining ahole through the stem to a stem fuel passage adjacent a fuel inletfluidly connected to the stem fuel passage, the fuel inlet located at afitting portion of the stem at an end of the stem opposite the injectorhead; and metallurgically bonding a resonator to the fitting portion,the resonator including a resonator body forming a resonator cavityfluidly connected to the stem fuel passage adjacent to the fuel inlet atthe fitting portion.
 19. The method of claim 18, wherein metallurgicallybonding the resonator to the fitting portion includes metallurgicallybonding a resonator wall of the resonator body to the fitting portion,wherein the resonator body includes a resonator cap integral to theresonator wall, and wherein the hole forms a resonator neck passage thatfluidly connects the resonator cavity to the stem fuel passage adjacentto the fuel inlet.
 20. The method of claim 18, wherein the resonatorincludes a resonator tube extending from the resonator body, whereinmetallurgically bonding the resonator to the fitting portion includesinserting the resonator tube into the hole and metallurgically bondingthe resonator tube to the stem, and wherein the resonator tube includesa resonator neck passage that fluidly connects the stem fuel passage tothe resonator cavity.